1. Field of the Invention
The present invention relates to a hydrodynamic bearing assembly and a motor including the same.
2. Description of the Related Art
In general, a hard disk drive (HDD), an information storage device, reads data stored on a disk or writes data to a disk using a read/write head.
The hard disk drive requires a disk driving device capable of driving the disk. In the disk driving device, a small-sized spindle motor is used.
The small spindle motor uses a hydrodynamic bearing assembly. A lubricating fluid is interposed between a shaft and a sleeve of the hydrodynamic bearing assembly, such that the shaft is supported by fluid pressure generated in the lubricating fluid.
In addition, the lubricating fluid injected into the hydrodynamic bearing assembly may be leaked to the outside by an impact or an amount of lubricating fluid may be reduced by evaporation. Due to this phenomenon, the hydrodynamic bearing may fail to generate pressure, a problem in performance and a lifespan of the spindle motor may be generated.
Therefore, research into a technology for significantly improving performance and a lifespan of a spindle motor by preventing leakage of lubricating fluid in a hydrodynamic bearing assembly has been urgently demanded.